Scissors



May 1, 1934.

M. PARKER ET AL SCISSORS Filed March 4, 1932 2 Sheets-Sheet l fiTOR M MOWI ATTORN EYS May 1, 1934. M. PARKER El AL SCISSORS Filed March 4, 19322 Sheets-Sheet 2 ATTORNEY-.5

Patented May 1, 1934 UNITED STATES PATENT OFFECE'.

SCIS SOR-S Application March 4, 1932, Serial No. 596,744

14 Claims. (01. 30-43) This invention relates to improvements inscissors, particularly detachable blade scissors such as described inPatent No. 1,814,959 issued to one of the present applicants.

The blades illustrated in that patent are so fine and wire-like that itis difficult to insert the thumb nail between the side of the blade atits inner end and the supporting shank or frame to free it from thelatch and permit withdrawal. In accordance with the present invention wefacilitate withdrawal of the blade by terminating the blade-supportingbead short of the inner or butt end of the blade so as to leave the buttexposed and accessible and laterally unsupported fora short distance sothat it may be flexed sidewise. A notch in the blade cooperates With alatch on the frame to prevent accidental Withdrawal, while to remove theblade intentionally it is necessary only to open the scissors to theirwide open position-thereby exposing the inner or butt end of eachblade-and push outward and to the side against the exposed inner end ofthe blade with a coin or other convenient tool.

With the butt ends of the blades exposed and terminating short of theintersection of the operative edges when the scissors are in wide openposition, it might happen that, in closing, the two opposing butt endswould interfere and so prevent the closing of the scissors. In order toavoid this we have constructed our scissors so that the cutting edgescannot touch until after the frames have closed slightly beyond the buttends of the blades. We do this by providing a pair of interacting camsurfaces, one cam on the inner face of each frame between the pivotscrew and the cutting edge, so positioned as to ride upon each other asthe exposed butt ends of the blades pass, thus tilting the frames toseparate the blades. In closing, when the ends-of the blades havepassed, the cams move apart and the cutting edges come into shearingcontact. As a further improvement we facilitate the mounting of theblade on the bead by cutting away, at its inner end, the lower flangewhich enters the undercut portion of the bead. Thus it is necessary onlyto place the inner end of the blade over the tip of the bead and shoveinward. By this means the flange is easily and automatically alignedwith the undercut groove which defines the'bead.

In the accompanying drawings we have illus trated a preferred embodimentof our invention.

.In these drawings Figure 1 is an elevation of a pair of scissorsconstructed in accordance with the present invention; Figure 2 is anenlarged detail of one frame showing the inner end of a blade mountedthereon; Figure 3 is a view similar to Figure 2 with the blade removed;Figure 4 is a still'further enlarged vertical section taken along line44 of Figure 2; Figure 5 is an enlarged horizontal section through theinner end of the blade and its supporting bead showing the latchconstruction and taken along line 5-5 of Figure 4; Figure 6 is aperspective view of the inner end of the blade; Figure 7 is an enlargedsection taken along line 7--7 of Figure 2; Figure 8 is an enlarged viewshowing the scissors in wide open position with the butt ends of theblades exposed for removal, and Figure 9 is a similar view showing theposition of the parts just after the butt ends of the blades have passedeach other in closing. 7

The scissors shown in Figure 1 comprise frames 1 pivoted together bymeans of the ordinary pivot screw 2. Extending along the operativeedgeof each frame from the tip to a point somewhat in advance of thepivot screw is a bead or rail 3 defined by a shoulder 4.extending along'the back of the shank and by a groove 5 in its shear face. On this beadis mounted a detachable flexible blade 6, of the type illustrated inPatent No. 1,814,959, provided with a flange '7 seated upon the shoulder4 and a flange 8 seated within the groove 5. As illustrated most clearlyin Figure 4 the rail or bead 3 is inclined slightly toward the plane ofthe shear face so that the blade 6, when mounted, is canted, say 5 or10, with reference to the shear face, the sharpened edge 9 of the bladelying above the plane of the inner face of the frame.

As illustrated most clearly in Figures 3 and 7, the inner end of thebead 3 is cut away at 10 so that the flange 4 has no lateral supportbeyond that point, and the inner end of the blade can, therefore, beflexed inwardly away from the inner face of the frame. The cut-awayportion of the bead extends well beyond the butt end of the bladeleaving that end open and exposed as shown in Figure 2. y

Inorder to prevent the blade from slipping outward along the bead whenin use, we prov1de a latch 11 near the inner end of the groove 5 whichcooperates with a cut-out portion 12 in the flange 8 and adjacent web ofthe blade. As the blade is slid inward along the bead, that section ofthe blade beyond the cut-out rides up the inclined outer face of thelatch 11 and snaps into position behind it, as shown in Figure 5.Although there is little possibility of further inward movement of theblade after its inner end has passed the cams 16' and 15'.

latch 11, we nevertheless make this impossible by providing the wall 14beyond the' notch 11 against which the inner end of the flange 8 mayabut, thus forming a lock against movement in either direction.

In order to facilitate mounting the blade upon the bead, which is doneby a longitudinal sliding movement toward the. pivot, we cut away theflange 8 and a portion of the web of the blade at its inner end asillustrated at 13 in Figure 6. With a blade so constructed it isnecessary only to place the end of the blade over the tip of the beadand. then slide it inward, the alignment of the flange 8 with the groove5 being thus automatically effected.

In order to remove the blade when dulled the frames are swung to theirwide open position, as illustrated in Figures 1 and 8, a coin or otherconvenient tool applied to the butt end of the blade and pressureexerted to swing the laterally un-- supported inner end free of thelatch 11 and at the same time to slide the blade outward along the bead.

With the butt ends of the blades exposed, as illustrated in Figures 1and 8, these inner ends would be very likely to interfere with eachother and prevent closing of the scissors. To prevent this wehaveprovided the inner faces of the frames with cams 15 and 15', one onthe inner face of each frame between the pivot screw and the inner endof the blade, so positioned that, as the inner ends of the bladesapproach each other, these cams ride upon each other and tilt the framesjust sufficiently to separate the blades. After the ends of the bladeshave passed, during closing, the cams ride down and the cutting edgesare again brought into contact. These cams 15 and 15, therefore, make itimpossible for the butt ends of the blades to interfere.

In Figures 8 and 9 we have also illustrated two additional cams 16 and16' on the inner faces of the frames beyond the pivot screw. Thesecooperate to urge the cutting edges into contact throughout the shearingstroke. These cams are so placed that they cannot come into operationuntil the cams 15 and 15 have separated. Likewise, the cams 15 and 15'cannot come into operation while the cams 16 and 16 are in contact. InFigure 9 we have illustrated the frames with the cams l6 and 16 movinginto cooperative relationship and cams 15 and 15' moving out of suchrelationship. The angular distance between the forward end of cam 16 andthe rear end of cam 15 is not less than 180. The same is also true forThe cams l6 and 16 are described and claimed more particularly in our copending application, Serial No. 596,742 filed concurrently herewith.

We claim:

1. Scissors comprising a frame, a'flexible blade slidably mounted on theoperative edge thereof, means for supporting the blade against lateralflexure except for a short distance adjacent its inner end, and a latchengaging the inner end of the blade beyond the lateral support forholding the blade against longitudinal displacement.

2. Scissors comprising a frame, a bead extending alow the operative edgethereof, a flexible blade slidably mounted upon the bead and extendingbeyond the inner end of the bead, and a latch engaging the blade beyondthe inner end of the head for holding the blade against longitudinaldisplacement, the frame being cut away beyond the inner termination ofthe blade to expose its butt end. I

3. Scissors comprising a frame, a bead extending along the operativeedge of the frame, a longitudinally slidable blade mounted upon thebead, a latch engaging the blade adjacent its inner end for preventinglongitudinal displacement, and a cut-out section at the inner end of thebead extending from a point within the blade to a point beyond wherebythe butt end of the blade is exposed and whereby the butt end of theblade may be flexed to disengage the latch.

4. Scissors comprising a pair of pivoted frames, a bead extending alongthe operative edge of each frame, flexible blades slidably mounted uponthe beads, ;a latch engaging each blade adjacent its inner end forpreventing longitudinal dis placement, a cut-out section at the innerend of each bead extending from a point within each blade to a pointbeyond, whereby the butt end of each blade is exposed and whereby thebutt end of each blade may be flexed to disengage the latch, and meansfor keeping the butt ends of the blades out of contact as they pass.

5. Scissors comprising a pair of pivoted frames, the cutting edge of oneframe terminating in an exposed butt end short of the intersection ofthe frames when the scissors are in wide open position, and means forkeeping said exposed butt end out of contact with the other cutting edgeas they pass each other.

6. Scissors comprising a pair of pivoted frames having cutting edgesterminating in exposed butt ends short of the intersection of the frameswhen the scissors are in wide open position, and cams on the frames forseparating the frames as the exposed butt ends of the cutting edges passeach other.

7. Scissors comprising a pair of pivoted frames having cutting edgesterminating in exposed butt ends short of the intersection of the frameswhen the scissors are in wide open position, cams on the frames forseparating the frames as the exposed butt ends pass each other while thescissors are being opened, and other cams for urging the blades intocontact after their butt ends have passed each other while the scissorsare being closed.

8. Scissors comprising a pair of pivoted frames, longitudinally slidableblades mounted on the operative edges thereof and terminating short ofthe intersection of the operative edges when the scissors are in wideopen position, and means for keeping the blades out of contact as theirinner ends pass each other.

9. Scissors comprising a pair of pivoted frames, blades removablymounted thereon terminating in exposed butt ends short of theintersection of the operative edges when the scissors are in wide openposition, and means for keeping the butt ends of the blades out ofcontact as they pass each other.

10. Scissors comprising a pair of pivoted frames, a bead extending alongthe operative edge of each frame, a blade longitudinally slidable uponeach bead and terminating in an exposed butt end short of theintersection of the operative edges when the scissors are in wide openposition, and cams on the inner faces of the frames for separating theblades as their exposed butt ends pass.

11. Scissors comprising a pair of pivoted frames, longitudinallyslidable blades mounted on the operative edges thereof and terminatingshort of the intersection of the operative edges when the scissors arein wide open position, means for keeping the blades out of contact astheir inner ends pass each other, and other means for urging the bladesinto contact after their inner ends have passed each other while thescissors are being closed.

12. Scissors comprising a pair of pivoted frames, a flexible bladeslidably mounted on the operative edge of each frame, means forsupporting each blade against lateral flexure except for a shortdistance adjacent its inner end, a latch engaging the inner end of eachblade beyond the lateral support for holding the blade againstlongitudinal displacement, a cut-out section in each frame beyond theinner termination of the blades to expose their butt ends, and cams onthe inner faces of the frames for separating the blades as their exposedbutt ends pass.

13. Scissors comprising a pair of pivoted frames, a bead extending alongthe operative edge of each frame, a blade longitudinally slidable uponeach bead and terminating at a point beyond the inner end of the beadbut short of the intersection of the operative edges when the scissorsare in wide open position, cooperating cams on the inner faces of theframes adjacent the pivot for separating the blades as their butt endspass each other while the scissors are being opened, and other cams forurging the blades into contact after their butt ends have passed eachother while the scissors are being closed.

14. A detachable blade for scissors having a longitudinal recess shapedto embrace an undercut bead on the scissors shank, a flange to hold theblade against lateral displacement, and a cutout in the inner end of theflange whereby the lead end of the blade can be placed laterally overthe tip of the bead to align the blade and bead for a longitudinalsliding interfit.

MORGAN PARKER. JOHN W. B. LADD.

Ill?

